There is dust inside a640 lens, how to solve it?

I recommend you to go to Xiao Yuan Digital Photography Equipment City, which is opposite to the railway station.

If it's Canon's ... Nimei's house on the first floor can ask them to help you clean it, and there are many professional shops on the second floor to help you clean it. You can go and see ~ ~ ~

It won't take long and the cost is not high. Just wash it clean ~ ~ ~ it's not expensive. If your Canon camera is still under warranty, maybe you can clean it for free ~